Challenges | CodeForge

ID	Title	Difficulty	Actions
1	Two Sum Find two numbers adding up to target.	EASY	View \| Edit
2	Valid Parentheses Check if parentheses are balanced.	EASY	View \| Edit
3	Merge Intervals Merge overlapping intervals.	MEDIUM	View \| Edit
4	Best Time to Buy and Sell Stock Max profit from single stock trade.	EASY	View \| Edit
5	Binary Tree Level Order Traversal Traverse levels of a binary tree.	MEDIUM	View \| Edit
6	LRU Cache Design a least-recently-used cache.	HARD	View \| Edit
7	Longest Substring Without Repeating Characters Find longest unique-char substring.	MEDIUM	View \| Edit
8	Climbing Stairs Count ways to climb stairs.	EASY	View \| Edit
9	Number of Islands Count islands in a grid.	MEDIUM	View \| Edit
10	Median of Two Sorted Arrays Find median of two sorted arrays.	HARD	View \| Edit